The invention relates to a dual clutch transmission with modifiable gear speeds and use of the transmission for at least two transmission variations.
From the DE 10 2004 012 909 A1 a dual clutch transmission is known comprising a first group of fixed wheels and a second input shaft with a second group of fixed wheels. The fixed wheels are engaged by loose wheels that are provided on a first intermediate shaft or a second intermediate shaft, respectively. Each loose wheel that is engaged by a fixed wheel from the first group of fixed wheels can be assigned to an odd numbered forward gear I, III, V, VII. Accordingly, each loose wheel that is engaged by a fixed wheel from the second group of fixed wheels can be assigned to an even numbered forward gear II, IV, VI.
By means of gear shift clutches, the individual loose wheels can be connected in a non-rotatable manner with the respective intermediate shaft. Therefore, a torque flow from one of the input shafts via the fixed wheel and a loose wheel that is engaged by the fixed wheel to one of the intermediate shafts is possible, wherein for the torque transmission to the intermediate shaft the loose wheel is activated by means of a corresponding gear shift clutch.
The dual clutch transmission according to the DE 10 2004 012 909 A1 comprises two so-called interdependences. One interdependence is established when two loose wheels are engaged by one and the same fixed wheels. While one interdependence is established by means of the loose wheels of a fifth forward gear or a seven forward gear, respectively, with the respective fixed wheel, the other interdependence is created by the loose wheels of a fourth forward gear IV or a sixth forward gear VI, respectively.
By providing one or more interdependences dual clutch transmissions having a low axial size can be designed, that being preferred in motor vehicles with combustion engines that are disposed in a transverse direction. One disadvantage of this interdependence is that with changing the transmission ratio of one forward gear, also the transmission ratio of the other forward gear that is established by the other loose wheel of the same interdependence is changed. This makes it difficult to adapt a dual clutch transmission that has been optimized with regard to the transmission gaps to a particular combustion engine in a motor vehicle to a different combustion engine with a different rotational speed characteristic or a different range of the rotational speeds in the optimal manner. This might result in substantial modifications of the design of the dual clutch transmission and therefore result in high costs.